This invention relates to pole-mounted luminaires and more particularly to a mounting system for easily and securely mounting luminaires to a pole.
Exterior luminaires used for lighting paths, sidewalks, parking lots or the like are typically secured to a tubular post or pole which extends vertically upward from the ground. Typically, a number of luminaires are secured to the top end of the post to provide area lighting for the parking lot, path, sidewalk or the like. The luminaire assemblies must be securely mounted to the top of the pole so as to resist vibration, movement, or twisting caused by the wind or other forces over a long period of time.
In the past, each luminaire assembly has been attached to a mounting fixture which is then inserted axially into the open top end of the tubular pole. Thereafter, a pair of holes is drilled by the installer transversely, that is, diametrically, through both the sidewalls of the tubular pole and the mounting fixture which is inserted therein. Bolts are then inserted through the holes and anchored in place by nuts or other mechanical fasteners to secure the luminaire assembly to the pole and prevent twisting thereof relative to the pole.
One problem associated with this prior system is that the mounting fixture which is inserted into the top of the tubular pole must have clearance to facilitate insertion. This clearance permits the mounting fixture to vibrate within the pole in response to wind-induced vibration of the luminaires. Due to manufacturing variations in the pole and mounting fixture, the actual size of the opening in the tubular pole varies substantially from the nominal or design dimension. Therefore, the difference between the size of the mounting fixture and the pole must include a margin of error or safety factor to ensure that the mounting fixture will fit inside any given nominal size pole and thereby minimize adjustments required by the installer. As a result of this arrangement, the bolts extending through the pole and mounting fixture do not dampen the vibration and the resulting noise which is generated by the luminaries. In addition to creating noise, the vibration of the mounting fixture causes it to become loose relative to the pole, resulting in the need for frequent repair and/or replacement and/or damage to the luminaire assembly.
Another problem with the prior mounting system is that it requires several different tools and a considerable amount of work and time to complete the installation. Further, complicating the installation procedure for luminaire assemblies is that the luminaire assemblies are typically installed on the pole after the pole is mounted in the ground, thereby requiring the installation procedure to be performed high above the ground. This presents potentially dangerous and difficult working conditions that make the installation of the luminaire assemblies even more difficult and time consuming.